Computational models of laminates are being developed with the aid of micromechanics models. The latter are used to selectively study important failure modes. One such failure mode is fiber kinking in compression dominated loading. Immediately after kinking, it is frequently observed that adjacent plies undergo delamination. In this project, a methodology is being developed to delineate and understand the various parameters that either favor delaminaton and/or kinking when subjected to compression. In order to accomplish this task, cohesive zone models can be used to advantage. However, when cohesive zone models are used with bi-materials, several questions pertaining to the partition of crack tip energy and how these energies are computed become important. Because of this, we are re-examining some of the pioneering work done by Barenblatt and others in formulating the concepts and ideas that lead to the currently used cohesive zone models in finite element packages.
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